Interesting. My first thought was that perhaps the installation hadn’t been successful (or the CUDA paths weren’t set up correctly), but it sounds like you have a good handle on that. Another possibility is that your GPUs are set in process exclusive mode… Have a look at this response here by my colleage Stephan. LogicError: cuCtxCreate failed: invalid device ordinal
(Though you shouldn’t need to downgrade your CUDA version, as recommended in that other thread). Try that nvidia-smi command and see if that resolves it.
Harris